From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DA59C352A3 for ; Fri, 14 Feb 2020 01:51:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4DEFD222C2 for ; Fri, 14 Feb 2020 01:51:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581645092; bh=WDRqGLlGcgsGtJnCUjmJ8SBRFPhZLI4nnSahdtCOJpY=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=OuihThgDzUBRNIo9t3F2H1fmoC952qbbE6EMyUr4JyLGlxS7oWkZk2HSyX0NrryPU l5nuL+Qnpz4p/5MaEC2mJETf1pnmVFL2TOprt69XsWAwEL1Zx8/VYhWtwbnWy6ZXrr CsWKMGwU452eeo8v9eMHIXZxzahfb43CPBnIbhY8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728200AbgBNBvb (ORCPT ); Thu, 13 Feb 2020 20:51:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:51468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727988AbgBNBvb (ORCPT ); Thu, 13 Feb 2020 20:51:31 -0500 Received: from mail-qv1-f49.google.com (mail-qv1-f49.google.com [209.85.219.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 95D8224649; Fri, 14 Feb 2020 01:51:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581645090; bh=WDRqGLlGcgsGtJnCUjmJ8SBRFPhZLI4nnSahdtCOJpY=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=HtJglxyTjgkyhe4CdWu2WxkDcE1vpcbE2FQM+j+/LT3a3sPVxwe4B50H6W+JTFKMB 8UX72jZ6DWHQO9gMz2QLuDNkYpBreBVCb99ZsN1DIYDGdslV2tEZUFvz2K2H29uqep NgBRCfWK3CQsmLXp+IpnCygmJPeRzhieeOkihNTQ= Received: by mail-qv1-f49.google.com with SMTP id m5so3609773qvv.4; Thu, 13 Feb 2020 17:51:30 -0800 (PST) X-Gm-Message-State: APjAAAU9dBWPgKdFOIVVPkAAbR2vUc5VqJvbzyIwGHNVkCDlJkq820GB 9vypOK6SzdAAzBCnMG2sUi2zW9tZNyQzGhsuLg== X-Google-Smtp-Source: APXvYqyTjLz0Q5iJr0U8tlUZFBpbfIYW2iYnW0ja4OOrPVoI4LcvA1j0mwSJRTx6VSFky+W9OzdHXzwuqOuZ2A/a70w= X-Received: by 2002:a05:6214:11ac:: with SMTP id u12mr301052qvv.85.1581645089662; Thu, 13 Feb 2020 17:51:29 -0800 (PST) MIME-Version: 1.0 References: <20200214004413.12450-1-john.stultz@linaro.org> In-Reply-To: <20200214004413.12450-1-john.stultz@linaro.org> From: Rob Herring Date: Thu, 13 Feb 2020 19:51:18 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC][PATCH] driver core: Extend returning EPROBE_DEFER for two minutes after late_initcall To: John Stultz Cc: lkml , Alexander Graf , "Rafael J. Wysocki" , Kevin Hilman , Ulf Hansson , Pavel Machek , Len Brown , Todd Kjos , Bjorn Andersson , Greg Kroah-Hartman , "open list:THERMAL" Content-Type: text/plain; charset="UTF-8" Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Thu, Feb 13, 2020 at 6:44 PM John Stultz wrote: > > Due to commit e01afc3250255 ("PM / Domains: Stop deferring probe > at the end of initcall"), along with commit 25b4e70dcce9 > ("driver core: allow stopping deferred probe after init") after > late_initcall, drivers will stop getting EPROBE_DEFER, and > instead see an error causing the driver to fail to load. > > That change causes trouble when trying to use many clk drivers > as modules, as the clk modules may not load until much later > after init has started. If a dependent driver loads and gets an > error instead of EPROBE_DEFER, it won't try to reload later when > the dependency is met, and will thus fail to load. > > Instead of reverting that patch, this patch tries to extend the > time that EPROBE_DEFER is retruned by two minutes, to (hopefully) > ensure that everything has had a chance to load. I think regulators already has some delay like this. We should use the same timeouts. We also have the 'deferred_probe_timeout' cmdline option. It's deemed a debug option currently, but we could change that and change the default. > Specifically, on db845c, this change allows us to set > SDM_GPUCC_845, QCOM_CLK_RPMH and COMMON_CLK_QCOM as modules and > get a working system, where as without it the display will fail > to load. > > Cc: Alexander Graf > Cc: Rob Herring > Cc: "Rafael J. Wysocki" > Cc: Kevin Hilman > Cc: Ulf Hansson > Cc: Pavel Machek > Cc: Len Brown > Cc: Todd Kjos > Cc: Bjorn Andersson > Cc: Greg Kroah-Hartman > Cc: linux-pm@vger.kernel.org > Fixes: e01afc3250255 ("PM / Domains: Stop deferring probe at the end of initcall") > Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") We can debate the design, but those work as designed. So Fixes? > Signed-off-by: John Stultz > --- > drivers/base/dd.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index b25bcab2a26b..35ebae8b65be 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -311,6 +311,12 @@ static void deferred_probe_timeout_work_func(struct work_struct *work) > } > static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func); > > +static void deferred_initcall_done_work_func(struct work_struct *work) > +{ > + initcalls_done = true; > +} > +static DECLARE_DELAYED_WORK(deferred_initcall_done_work, deferred_initcall_done_work_func); > + > /** > * deferred_probe_initcall() - Enable probing of deferred devices > * > @@ -327,7 +333,7 @@ static int deferred_probe_initcall(void) > driver_deferred_probe_trigger(); > /* Sort as many dependencies as possible before exiting initcalls */ > flush_work(&deferred_probe_work); > - initcalls_done = true; > + schedule_delayed_work(&deferred_initcall_done_work, 120 * HZ); > > /* > * Trigger deferred probe again, this time we won't defer anything > -- > 2.17.1 >